1.Tính
a. A= 219. 273 + 15 . 49 . 94/ 69 . 210 + 1210
b. B= 36 . 454- 1513 : 59/274. 253+ 456
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Lời giải:
\(P=\frac{2^{19}.27^3+15.4^9.9^4}{6^9.2^{10}+12^{10}}\\ =\frac{2^{19}.3^9+3.5.2^{18}.3^8}{2^9.3^9.2^{10}+2^{20}.3^{10}}\\ =\frac{2^{19}.3^9+2^{18}.3^9.5}{2^{19}.3^9+2^{20}.3^{10}}\\ =\frac{2^{18}.3^9(2+5)}{2^{19}3^9(1+2.3)}\\ =\frac{1}{2}\)
\(a,4^9:4^4=4^5\\b,17^8:17^5=17^3\\ c,2^{10}:8^2=2^{10}:2^6=2^4\\ d,18^{10}:3^{10}=2^{10}\cdot3^{20}:3^{10}=2^{10}\cdot3^{10}=6^{10}\\ e,27^5:81^3=3^{15}:3^{12}=3^3 \)
\(f,10^6:100=10^6:10^2=10^4\\ g,5^9:25^3=5^9:5^6=5^3\\ h,4^{10}:64^3=4^{10}:4^9=4\\ i,2^{25}:32^4:18^4:9^4=2^{25}:2^{20}:2^4:3^8:3^8=2\)
b: \(\dfrac{4^5\cdot9^4-2\cdot6^9}{2^{10}\cdot3^8+6^8\cdot20}\)
\(=\dfrac{2^{10}\cdot3^8-2^{10}\cdot3^9}{2^{10}\cdot3^8+3^8\cdot2^{10}\cdot5}\)
\(=\dfrac{2^{10}\cdot3^8\left(1-3\right)}{2^{11}\cdot3^9}\)
\(=\dfrac{1}{2}\cdot\dfrac{-2}{3}=\dfrac{-1}{3}\)
a)
49:44=45
178:175=173
210:82=210:24=26
1810:310=1510
275:813=315:312=33
b)106:102=104
59:56=53
410:643=4
225:324=225:220=25
184:94=94
\(4^9:4^4\)
=\(4^{9-4}\)
=\(4^5\)
\(17^8:17^5\)
=\(17^{8-5}\)
= \(17^3\)
\(2^{10}:8^2\)
\(=2^{^{ }10}:\left(2^3\right)^2\)
=\(2^{10}:2^6\)
\(=2^4\)
\(18^{10}:3^{10}\)
=\(\left(18:3\right)^{10}\)
=\(6^{10}\)
a) \(4^9:4^4\)
\(=4^{9-4}\)
\(=4^5\)
b) \(17^8:17^5\)
\(=17^{8-5}\)
\(=17^3\)
c) \(2^{10}:8^2\)
\(=2^{10}:\left(2^3\right)^2\)
\(=2^{10-6}\)
\(=2^4\)
d) \(18^{10}:3^{10}\)
\(=\left(18:3\right)^{10}\)
\(=6^{10}\)
e) \(27^5:81^3\)
\(=\left(3^3\right)^5:\left(3^4\right)^3\)
\(=3^{15}:3^{12}\)
\(=3^{15-12}\)
\(=3^3\)
f) \(10^6:100\)
\(=10^6:10^2\)
\(=10^{6-2}\)
\(=10^4\)
g) \(5^9:25^3\)
\(=5^9:\left(5^2\right)^3\)
\(=5^9:5^6\)
\(=5^{9-6}\)
\(=5^3\)
h) \(4^{10}:64^3\)
\(=4^{10}:\left(4^3\right)^3\)
\(=4^{10-9}\)
\(=4\)
i) \(2^{25}:32^4:18^4:9^4\)
\(=\left(2^{25}:2^{20}\right):\left(18^4\cdot9^4\right)\)
\(=2^5:9^8:2^4\)
\(=2:9^8\)
\(=\dfrac{2}{9^8}\)
a: \(\left(24-234\right)+\left(234-24-77\right)\)
\(=24-234+234-24-77\)
\(=\left(24-24\right)+\left(234-234\right)-77\)
=0+0-77
=-77
b: \(\left(13-135+49\right)-\left(13+49\right)\)
\(=13-135+49-13-49\)
\(=\left(13-13\right)+\left(49-49\right)-135\)
=0+0-135
=-135
c: \(159-524-\left(59-424\right)\)
\(=159-524-59+424\)
\(=\left(159-59\right)-\left(524-424\right)\)
=100-100
=0
d: \(\left(36+79\right)+\left(145-79-36\right)\)
\(=36+79+145-79-36\)
\(=\left(36-36\right)+\left(79-79\right)+145\)
=0+0+145
=145
e: \(334-\left(117+234\right)+\left(42+117\right)\)
\(=334-117-234+42+117\)
\(=\left(334-234\right)+\left(117-117\right)+42\)
=100+0+42
=142
f: \(271-\left[\left(-43\right)+271-\left(-17\right)\right]\)
\(=271+43-271+\left(-17\right)\)
\(=\left(271-271\right)+\left(43-17\right)\)
=0+26
=26
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